1. Field of the Invention
This invention relates to a loader work machine having a working implement such as a front loader attached to a front portion of a vehicle body such as a tractor.
2. Description of the Related Art
In some conventional loader work machines, side frames disposed on opposed lateral sides of the vehicle body for supporting booms are detachably attached to respective mounting frames on the lateral sides by fitting engaging pins into respective recesses of receiving members and inserting mounting pins through respective bosses on the lateral sides. In such a conventional loader work machine, each of the mounting frames includes a mounting plate to the vehicle body, a support base projecting laterally outwardly from the mounting plate and a main frame fixed to a laterally outward end of the support base. Each main frame is formed to have a box shape by welding a plurality of metal plate members (see JP-A-2001-132006 and JP-A-2000-309940, for example).
The above conventional loader work machine has room for improvement with regard to low productivity, since each main frame is formed of many welded parts with large weld lengths, and to difficulty in securing dimensional accuracy owing to welding distortions.